摘要目的:观察放射线对体外培养棘球蚴的杀伤作用及对其生长阻滞和DNA损伤45α（growth arrest and DNA damage 45 alpha，Gadd45α）mRNA表达的影响。方法:体外培养自然感染的羊肝脏中的棘球蚴，分为7组，分别以0（对照）、20、40、60、80、100、120 Gy的6兆电子线（6 MeV）进行1次放射。放射线照射后培养1、3、5、7 d时，光镜下观察棘球蚴的生长情况；采用反转录-聚合酶链反应（RT-PCR）法测定放射线照射后培养7 d时，对照，20、40、60 Gy组棘球蚴Gadd45α mRNA表达水平。结果:各剂量组放射线照射后1、3、5、7 d时，光镜下棘球蚴结构崩解，勾突脱落，且棘球蚴死亡率与放射线照射剂量呈正相关（ r = 0.81， P < 0.05）。放射线照射后培养7 d时，与对照组（100.00 ± 0.00）比较，20、40、60 Gy组棘球蚴Gadd45α mRNA表达水平明显升高（279.74 ± 80.08、759.38 ± 160.98、1 666.68 ± 316.36， P均 < 0.01），且与放射线剂量呈正相关（ r = 0.93， P < 0.01）。 结论:放射线照射对体外培养的棘球蚴有一定的杀伤作用，且与放射线的剂量存在一定的量效关系；Gadd45α基因可能参与放射线所致体外杀伤棘球蚴的分子机制。

abstractsObjective:To investigate the killing effect of radiation on echinococcus in vitro culture and its effect on the mRNA expression of growth arrest and DNA damage 45 alpha (Gadd45α) gene. Methods:Echinococcus from naturally infected sheep liver was cultured in vitro and divided into 7 groups. The echinococcus was irradiated with 6 MeV at doses of 0 (control), 20, 40, 60, 80, 100, and 120 Gy, respectively. The growth of echinococcus was observed under light microscope at 1, 3, 5 and 7 d after the radiation. The expression of Gadd45α mRNA in control, 20, 40 and 60 Gy groups of echinococcus was detected by RT-PCR technique at 7 d after the radiation. Results:The disintegration and exfoliation of echinococcus were observed under light microscope at 1, 3, 5 and 7 d after the radiation, and the death rate of echinococcus was positively correlated with the radiation dosages ( r = 0.81, P < 0.05). After the radiation at 7 d, compared with the control group (100.00 ± 0.00), the mRNA expression levels of Gadd45α in echinococcus of 20, 40, and 60 Gy groups were significantly increased (279.74 ± 80.08, 759.38 ± 160.98, 1 666.68 ± 316.36, P < 0.01), and it was positively correlated with the radiation dosages ( r = 0.93, P < 0.01). Conclusion:Radiation has a certain killing effect on echinococcus cultured in vitro, and there is a certain dose-effect relationship with the radiation dosages, and Gadd45α gene may be involved in the molecular mechanism of radiation-induced killing of echinococcus in vitro.